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Ernesto headed for Florida

By: Dr. Jeff Masters, 9:16 PM GMT on August 28, 2006

Ernesto continues its trek across Cuba, and has dumped over 8 inches so far at Guantanamo. No reports of injuries or damage have come out of Cuba thus far, and Ernesto's top winds have only been 40 mph for the duration of its trek. The storm has maintained a large envelope of spinning clouds and moisture around its center, and is already starting to fire up some heavy thunderstorms north of Cuba as its center prepares to emerge into the Florida Straits. However, the system is very disorganized at present and will not be able to strengthen quickly once it moves over water.

The 12Z (8am EDT) model runs are all in, and they don't show any significant changes to the track or expected intensity of Ernesto for its Florida landfall. Ernesto is expected to pop off the Cuban coast tonight, cross the Florida Straits, and make landfall somewhere between Miami and Naples. The SHIPS intensity model is calling for Ernesto to be a tropical storm with 55 mph winds at landfall, while the GFDL model thinks Ernesto will be a Category 1 hurricane with 75-80 mph winds. The GFDL is probably too strong, since its 6 hour forecast verifying at 2pm today predicted 60 mph winds, and the real winds were only 40 mph. With only 18-36 hours over water, Ernesto's winds will most likely be in the 50-75 mph range at landfall. My best guess is for a very wet tropical storm with maximum winds of 60 mph hitting the Everglades.

The models' expectations of what might happen to the Carolinas later in the week are very different, since small changes in the forecast track put the storm over land where it weakens, or over the warm Gulf Stream, where it can intensify dramatically. The worst case model is the GFDL, which brings a strong Category 2 hurricane to the South Carolina coast Thursday night. The best case scenario is a total miss, with the storm going out to sea, as depicted by the Canadian model (although it's unclear if the storm might circle back and strike the coast next week).

Finally, my summary of the computer models and where to find them
I've put together a detailed desciption of the computer models we provide on the wunderground.com computer model plot for each tropical storm. A brief description of the important models is given, along with a web site to get the data from. I've linked this description page under the "My links" section at the right of my blog, and it is also available on the tropical page. Here's a condensed version:

Types of hurricane forecasting models
The best hurricane forecasting models we have are "global" models, that solve the mathematical equations governing the behavior of the atmosphere at every point on the globe. Models that solve these equations are called "dynamical" models. The four best hurricane forecast models--GFDL, GFS, UKMET, and NOGAPS--are all global dynamical models. These models take several hours to run on the world's most advanced supercomputers.

Non-global models
The BAMM model (Beta and advection model, medium layer) is included on wunderground.com's computer model page. The BAMM is a simple trajectory model that is very fast to run, and did the best of any individual model at 3-5 day track forecasts in 2005. Since this model is always available, we have included it along with the "big four". In general, one should not trust the BAMM model for the 1-2 day time period when output from "the big four" are available. "The big four" are generally not available for tropical disturbances, and for these situations we post plots of a number of other non-global models such as the LBAR, A98E, etc. All of these models are described in detail on NHC's web site.

Model performance in 2005
The National Hurricane Center issues annual verification reports comparing model performance to the official NHC forecast. The 2005 report found that the official NHC forecast was usually the best forecast, but was closely matched by taking an average of the "big four" models to come up with a consensus forecast. There are several techniques used to come up with these consensus model forecasts. The three best techniques are called the GUNA, CONU, and Florida State University Superensemble (FSSE). The FSSE model was developed by FSU with funding from the private company Weather Predict, and is not available to the public. The performance of the "big four", official forecast, and consensus models are plotted below.

Among individual track models, the GFDL did the best at 1-2 day forecasts, and the UKMET and BAMM (not shown in the plot) did very well at 4-5 day forecasts. For intensity, the SHIPS model (which we post in the lower right corner of the wunderground.com computer model forecast image) was the best performer. The SHIPS model is run using input from the GFS model.

Figure 1. Forecast performance in 2005, compared to a simple "Climatological and Persistence' (CLIPER) model. OFCL=Official NHC forecast. The "big four" global dynamical models are the GFDL, GFS, NOGAPS, and UKM (UKMET). Three methods of averaging the "big four" and coming up with a consensus model forecast are CONU, GUNA, and FSSE (Florida State Super Ensemble). The Official forecast and the three consensus forecasts did the best at all time periods. Among individual models, the BAMM model(not shown) did the best at the 3-5 day range, followed closely by the UKMET. The GFDL did the best in the 1-2 day range. Image credit: National Hurricane Center.

Next update
I'll be live on Internet Partnership Radio (www.ipr365.com), formerly Radio NHCWX, tonight at 8:30 pm EDT. I'll be talking with host Mike Watkins about Ernesto. My next blog will be Tuesday morning.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

2001. PBG00
we are not talking 3 days anymore..we are 24 hours out..I think they have a handle on it...And three ring circus is right..People just trying to get a rise out of people..ignore them..Maybe they have school today and will be gone in a bit.
Did it take the slite spin in the GOM and what will that do to the track I think it is moving it to the weast and we are going to have a weast coast storm
2003. ricderr
ok.....also...handing our free zanex samples....two a day to start you off....then..as the storm approaches...weather it be strong thunder-storm......a tropical storm..or minimal hurricane.....it will all be smooth sailing for you
Ernesto looks to be gaining strength every minute...why the increase in pressure?
Savanha I dont see nothing headed off to the north yet. In fact run the IR seems like the blob is gettin closer to Cuba. Got some driving to do today. Have a nice day. we need the rain anyway.
fla1963, not sure of the strength..but seems to have move west of its track....i might say a strong Tropical Storm....according to how long it stays over water.
fla1963, not sure of the strength..but seems to have move west of its track....i might say a strong Tropical Storm....according to how long it stays over water.
:::lining up for meds:::
sorry for the double post.....
It's not heading north. It's heading west, but it's already off the coast of Cuba, heading west.
when do the new models come out??
2013. PBG00
ricderr..I'll take a weeks worth!



Make up your mind..and stop the BS
2014. IKE
Per the 8am EDST NHC update..."Ernesto is moving toward the northwest near 14 mph...22 km/hr...and
this general motion is expected to continue for the next 24 hours.
On the forecast track...the center of Ernesto will be near the
Florida Keys or Southeast Florida by this evening. However...
squally rainbands will be moving onshore these areas during the

Reports from an Air Force reconnaissance aircraft indicate that the
maximum sustained winds remain near 45 mph...75 km/hr...with higher
gusts. Some strengthening is forecast during the next 24 hours.

Tropical storm force winds extend outward up to 85 miles...140 km
from the center.

The minimum central pressure reported by the reconnaissance plane
was 1007 mb...29.74 inches."....

The NHC even stated...continuing to move NW for the next 24 hours.

Pressure UP....to 1007 mb's.
2016. dewfree
who is talking gulf coast anywhere other then fl ounce past the keys west coast of florida is the only possible answer if it makes it to that point before the turn to the n e simply cause there is a frount heading southeast
Sorry, but my post is not an advertisement. It's a free view of eight minutes in a hurricane. This is a hurricane blog. You are an idiot.
2018. K8eCane
look guys
i have a question that is somewhat important to me
i live in wilmington nc (southeast coast) and i mean i am right on the coast
do you think any watches will be issued for here( as it will affect my work and my little boys school schedule this week)
i have no idea if they will or not but it would be nice to have a general idea
Good Morning All.......It does seem, as we have seen over the years, that the short term (24 hour) landfall/impact cones generated by NHC have been pretty accurate; while I also see what appears to be a Westward jog on the loops, I will go with the forcast track and continue to warn/advise my relatives and friends in Miami..I think that a large part of the rest of our day will be spent analizing intensity trends in-between the NHC advisories and looking for the telltale signs of rapid intensification, if at all, which may occur during the crossing between Cuba and Florida
ric.....tripple dose here please! Mornin' all.......ERnesto blow himself out yet.....please, oh, please say yes!
i see we have a troll this morning, im ready for what ernesto brings, even if its nothing
IOKE keeps on spining, and spining, and spining......

2024. PBG00
Just like they have repeatedly said for the last day
2026. dewfree
i believe wilmington will recieve alot of rain from eresto that is it for now
South Carolina Emergency Management Division has just went from Opcon 4 to Opcon 3 (Disaster or emergency situation likely or imminent) Link
2028. ricderr
that's the attitude say.....folks...it's done....you have 8 hours to make any last minute prep....regardless where you are in southeast or west florida.......your right or left wobbles...won't change much of the effects you will encounter..unless you truly believe it's heading due west out to the gulf of mexico...reagrdless of windspeed..it would appear that the chance of tornadoes will be high for most of florida this afternoon and throughout tomorrow morning..so keep yourself posted and your head down...now..the smoking lamp will be lit at 2100...that's when the ricderr bar will open and we will sit back...relax...and watch the wind blow
2029. IKE
It IS WNW....it moved .2N and .4W....in the last 3 hours.

Pressure up 2 mb's...from 1005 to 1007.

The key to the new update was the NHC saying it expected Ernie to CONTINUE moving NW for the next 24 hours.
2031. PBG00
o.k.nelly...and your "expertise" said it was absolutly no way a s fla storm..lets see..who to believe..who to believe..I'll take the guys with the meteorology degrees..and if i'm wrong...good!
2032. K8eCane
thanks dew for answering
it looks like a S FLorida storm to me, the NHC says so, so it looks like i wont be on here long, trolls, t-storms,and possibly more trolls
This WV loop shows the high pressure system to the north of ernesto starting to move east and flatten a bit on its western side. Ernesto's apparent more westerly motion should last that much longer IMO.

new blog up
like mosquitos in south fla - trolls are an annoying part of life in a blog - just ignore and swat (spam)
2037. dewfree
no one that i know or have read has said that the storm want be a south fl problem .what was said is that the track is west of the NHC track and of course that i blieve it will track up the west side of fl crashing across that is it . no matter where it track west or nw it still will effect south fl that is a given lol
Ernesto is right on the forecast track. The NHC has had the track right sense yesterday I don't see more than a slight change at most before landfall tonight. The intensity forecast is more complicated. I expected more intensification over night but land and dry air would not allow. Shear still seems low but the ULL is still feeding Ernesto some dry air. I expect some slow stengthening until this afternoon when Ernesto puts more distance between the ULL and Cuba. After Ernesto could very well intensify quickly into a strong tropical storm or weak cane.
2039. dewfree
storms sometimes increase pressure reorganizing it is common thing .
2040. wpieler
new blog started
2041. dewfree
the storm didnt get into the water till a couple of hours ago geez
I enjoy the variety of predictions, even those that seem far out. I always give more weight to the NHC. But, I realize their's is a prediction, too. So predict away (or guess). Just understand what you are doing. Don't get so married to your prediction that it effects your objectivity.

BTW, thanks to this site and personal observations, I was fully prepared for Ivan without having to fight the crowds(it was supposed to be a FL storm). If I had been wrong and the storm did not come our way, so what. I would have used the gas and eaten the food and maybe wasted $20 on batteries.
2043. dewfree
to set the record straight UKMET and GFS both show west side lol anything west of tip is west lol
2044. dewfree
SAYMOBEEL- correct in your assesment and agree totally .i feel like i have been defending the position of west coast fl and it is concievable and possible . but it doesnt have to go very far to achive that just past Layton and it will be just that a west coast storm lol
The COC is just starting to appear at the long range KBYX radar loop; the damn thing looks to be moving W or WNW!
2046. dewfree
the gfs and gfdlshow the land fall on the west side of fl between vinece and naples lol west coast storm lol
Looks like wew will be stepping up to the plate very soon. MM63

Ok i just got back from the Gym. All the news stations around here still have this thing going up the middle of the state missing the tampabay area. Yet when i see the radar look like its moving due west maybe a little north. it would almost have to stop and head Due North can some one explain this to me please
I am from Southwest Louisiana but live in TN. I have family on the coast from Melbourne, FL to Corpus Christi, TX so I keep up with the storms. From looking at the national map the front that is suppose to turn the storm north, north east then up the coast does not appear to be moving to fast. Will the ULL in the western Gulf influence the storm more than the trough associated with the cold front?
you see the left side of the signature, which is moving "left" or counter clockwise. The storm is actually moving n of NW now imho. Possibly even NNW
Live Hurricane Positions add-in for Google Earth. And it's not on StormSpammer dot com.